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-rw-r--r--fs/unicode/utf8-norm.c191
1 files changed, 171 insertions, 20 deletions
diff --git a/fs/unicode/utf8-norm.c b/fs/unicode/utf8-norm.c
index aa2980f26527..848b93e97f50 100644
--- a/fs/unicode/utf8-norm.c
+++ b/fs/unicode/utf8-norm.c
@@ -99,6 +99,38 @@ static inline int utf8clen(const char *s)
}
/*
+ * Decode a 3-byte UTF-8 sequence.
+ */
+static unsigned int
+utf8decode3(const char *str)
+{
+ unsigned int uc;
+
+ uc = *str++ & 0x0F;
+ uc <<= 6;
+ uc |= *str++ & 0x3F;
+ uc <<= 6;
+ uc |= *str++ & 0x3F;
+
+ return uc;
+}
+
+/*
+ * Encode a 3-byte UTF-8 sequence.
+ */
+static int
+utf8encode3(char *str, unsigned int val)
+{
+ str[2] = (val & 0x3F) | 0x80;
+ val >>= 6;
+ str[1] = (val & 0x3F) | 0x80;
+ val >>= 6;
+ str[0] = val | 0xE0;
+
+ return 3;
+}
+
+/*
* utf8trie_t
*
* A compact binary tree, used to decode UTF-8 characters.
@@ -159,7 +191,8 @@ typedef const unsigned char utf8trie_t;
* characters with the Default_Ignorable_Code_Point property.
* These do affect normalization, as they all have CCC 0.
*
- * The decompositions in the trie have been fully expanded.
+ * The decompositions in the trie have been fully expanded, with the
+ * exception of Hangul syllables, which are decomposed algorithmically.
*
* Casefolding, if applicable, is also done using decompositions.
*
@@ -179,6 +212,105 @@ typedef const unsigned char utf8leaf_t;
#define STOPPER (0)
#define DECOMPOSE (255)
+/* Marker for hangul syllable decomposition. */
+#define HANGUL ((char)(255))
+/* Size of the synthesized leaf used for Hangul syllable decomposition. */
+#define UTF8HANGULLEAF (12)
+
+/*
+ * Hangul decomposition (algorithm from Section 3.12 of Unicode 6.3.0)
+ *
+ * AC00;<Hangul Syllable, First>;Lo;0;L;;;;;N;;;;;
+ * D7A3;<Hangul Syllable, Last>;Lo;0;L;;;;;N;;;;;
+ *
+ * SBase = 0xAC00
+ * LBase = 0x1100
+ * VBase = 0x1161
+ * TBase = 0x11A7
+ * LCount = 19
+ * VCount = 21
+ * TCount = 28
+ * NCount = 588 (VCount * TCount)
+ * SCount = 11172 (LCount * NCount)
+ *
+ * Decomposition:
+ * SIndex = s - SBase
+ *
+ * LV (Canonical/Full)
+ * LIndex = SIndex / NCount
+ * VIndex = (Sindex % NCount) / TCount
+ * LPart = LBase + LIndex
+ * VPart = VBase + VIndex
+ *
+ * LVT (Canonical)
+ * LVIndex = (SIndex / TCount) * TCount
+ * TIndex = (Sindex % TCount)
+ * LVPart = SBase + LVIndex
+ * TPart = TBase + TIndex
+ *
+ * LVT (Full)
+ * LIndex = SIndex / NCount
+ * VIndex = (Sindex % NCount) / TCount
+ * TIndex = (Sindex % TCount)
+ * LPart = LBase + LIndex
+ * VPart = VBase + VIndex
+ * if (TIndex == 0) {
+ * d = <LPart, VPart>
+ * } else {
+ * TPart = TBase + TIndex
+ * d = <LPart, TPart, VPart>
+ * }
+ */
+
+/* Constants */
+#define SB (0xAC00)
+#define LB (0x1100)
+#define VB (0x1161)
+#define TB (0x11A7)
+#define LC (19)
+#define VC (21)
+#define TC (28)
+#define NC (VC * TC)
+#define SC (LC * NC)
+
+/* Algorithmic decomposition of hangul syllable. */
+static utf8leaf_t *
+utf8hangul(const char *str, unsigned char *hangul)
+{
+ unsigned int si;
+ unsigned int li;
+ unsigned int vi;
+ unsigned int ti;
+ unsigned char *h;
+
+ /* Calculate the SI, LI, VI, and TI values. */
+ si = utf8decode3(str) - SB;
+ li = si / NC;
+ vi = (si % NC) / TC;
+ ti = si % TC;
+
+ /* Fill in base of leaf. */
+ h = hangul;
+ LEAF_GEN(h) = 2;
+ LEAF_CCC(h) = DECOMPOSE;
+ h += 2;
+
+ /* Add LPart, a 3-byte UTF-8 sequence. */
+ h += utf8encode3((char *)h, li + LB);
+
+ /* Add VPart, a 3-byte UTF-8 sequence. */
+ h += utf8encode3((char *)h, vi + VB);
+
+ /* Add TPart if required, also a 3-byte UTF-8 sequence. */
+ if (ti)
+ h += utf8encode3((char *)h, ti + TB);
+
+ /* Terminate string. */
+ h[0] = '\0';
+
+ return hangul;
+}
+
/*
* Use trie to scan s, touching at most len bytes.
* Returns the leaf if one exists, NULL otherwise.
@@ -187,8 +319,8 @@ typedef const unsigned char utf8leaf_t;
* is well-formed and corresponds to a known unicode code point. The
* shorthand for this will be "is valid UTF-8 unicode".
*/
-static utf8leaf_t *utf8nlookup(const struct utf8data *data, const char *s,
- size_t len)
+static utf8leaf_t *utf8nlookup(const struct utf8data *data,
+ unsigned char *hangul, const char *s, size_t len)
{
utf8trie_t *trie = NULL;
int offlen;
@@ -228,8 +360,7 @@ static utf8leaf_t *utf8nlookup(const struct utf8data *data, const char *s,
trie++;
} else {
/* No right node. */
- node = 0;
- trie = NULL;
+ return NULL;
}
} else {
/* Left leg */
@@ -239,8 +370,7 @@ static utf8leaf_t *utf8nlookup(const struct utf8data *data, const char *s,
trie += offlen + 1;
} else if (*trie & RIGHTPATH) {
/* No left node. */
- node = 0;
- trie = NULL;
+ return NULL;
} else {
/* Left node after this node */
node = (*trie & TRIENODE);
@@ -248,6 +378,14 @@ static utf8leaf_t *utf8nlookup(const struct utf8data *data, const char *s,
}
}
}
+ /*
+ * Hangul decomposition is done algorithmically. These are the
+ * codepoints >= 0xAC00 and <= 0xD7A3. Their UTF-8 encoding is
+ * always 3 bytes long, so s has been advanced twice, and the
+ * start of the sequence is at s-2.
+ */
+ if (LEAF_CCC(trie) == DECOMPOSE && LEAF_STR(trie)[0] == HANGUL)
+ trie = utf8hangul(s - 2, hangul);
return trie;
}
@@ -257,9 +395,10 @@ static utf8leaf_t *utf8nlookup(const struct utf8data *data, const char *s,
*
* Forwards to utf8nlookup().
*/
-static utf8leaf_t *utf8lookup(const struct utf8data *data, const char *s)
+static utf8leaf_t *utf8lookup(const struct utf8data *data,
+ unsigned char *hangul, const char *s)
{
- return utf8nlookup(data, s, (size_t)-1);
+ return utf8nlookup(data, hangul, s, (size_t)-1);
}
/*
@@ -272,11 +411,13 @@ int utf8agemax(const struct utf8data *data, const char *s)
utf8leaf_t *leaf;
int age = 0;
int leaf_age;
+ unsigned char hangul[UTF8HANGULLEAF];
if (!data)
return -1;
+
while (*s) {
- leaf = utf8lookup(data, s);
+ leaf = utf8lookup(data, hangul, s);
if (!leaf)
return -1;
@@ -299,12 +440,13 @@ int utf8agemin(const struct utf8data *data, const char *s)
utf8leaf_t *leaf;
int age;
int leaf_age;
+ unsigned char hangul[UTF8HANGULLEAF];
if (!data)
return -1;
age = data->maxage;
while (*s) {
- leaf = utf8lookup(data, s);
+ leaf = utf8lookup(data, hangul, s);
if (!leaf)
return -1;
leaf_age = utf8agetab[LEAF_GEN(leaf)];
@@ -325,11 +467,13 @@ int utf8nagemax(const struct utf8data *data, const char *s, size_t len)
utf8leaf_t *leaf;
int age = 0;
int leaf_age;
+ unsigned char hangul[UTF8HANGULLEAF];
if (!data)
return -1;
+
while (len && *s) {
- leaf = utf8nlookup(data, s, len);
+ leaf = utf8nlookup(data, hangul, s, len);
if (!leaf)
return -1;
leaf_age = utf8agetab[LEAF_GEN(leaf)];
@@ -351,12 +495,13 @@ int utf8nagemin(const struct utf8data *data, const char *s, size_t len)
utf8leaf_t *leaf;
int leaf_age;
int age;
+ unsigned char hangul[UTF8HANGULLEAF];
if (!data)
return -1;
age = data->maxage;
while (len && *s) {
- leaf = utf8nlookup(data, s, len);
+ leaf = utf8nlookup(data, hangul, s, len);
if (!leaf)
return -1;
leaf_age = utf8agetab[LEAF_GEN(leaf)];
@@ -379,11 +524,12 @@ ssize_t utf8len(const struct utf8data *data, const char *s)
{
utf8leaf_t *leaf;
size_t ret = 0;
+ unsigned char hangul[UTF8HANGULLEAF];
if (!data)
return -1;
while (*s) {
- leaf = utf8lookup(data, s);
+ leaf = utf8lookup(data, hangul, s);
if (!leaf)
return -1;
if (utf8agetab[LEAF_GEN(leaf)] > data->maxage)
@@ -406,11 +552,12 @@ ssize_t utf8nlen(const struct utf8data *data, const char *s, size_t len)
{
utf8leaf_t *leaf;
size_t ret = 0;
+ unsigned char hangul[UTF8HANGULLEAF];
if (!data)
return -1;
while (len && *s) {
- leaf = utf8nlookup(data, s, len);
+ leaf = utf8nlookup(data, hangul, s, len);
if (!leaf)
return -1;
if (utf8agetab[LEAF_GEN(leaf)] > data->maxage)
@@ -533,10 +680,12 @@ int utf8byte(struct utf8cursor *u8c)
}
/* Look up the data for the current character. */
- if (u8c->p)
- leaf = utf8lookup(u8c->data, u8c->s);
- else
- leaf = utf8nlookup(u8c->data, u8c->s, u8c->len);
+ if (u8c->p) {
+ leaf = utf8lookup(u8c->data, u8c->hangul, u8c->s);
+ } else {
+ leaf = utf8nlookup(u8c->data, u8c->hangul,
+ u8c->s, u8c->len);
+ }
/* No leaf found implies that the input is a binary blob. */
if (!leaf)
@@ -557,7 +706,9 @@ int utf8byte(struct utf8cursor *u8c)
ccc = STOPPER;
goto ccc_mismatch;
}
- leaf = utf8lookup(u8c->data, u8c->s);
+
+ leaf = utf8lookup(u8c->data, u8c->hangul, u8c->s);
+ ccc = LEAF_CCC(leaf);
}
/*
generated by cgit (git 2.34.1) at 2024-05-23 07:40:31 +0000